A belief in a spiritual presence even in objects.
From the Latin word Animus, meaning soul or breath, animism, simply put, is the belief that objects have souls. This idea takes many forms, from the belief that there are spirits empowering places, to the idea that some ways of interacting with items can bring fortune or misfortune.
Animism is generally accepted as the most ancient form of personal belief and of overt worship, and elements of it still survive today in many forms. Some forms of animism believe that immaterial forces by-in-large drive all of reality.
To me, all humans have a need, driven by biological structures in our brain, for mysticism in some form or another. This may present itself as anything from centralized or solitary-"spiritual" religion, to philosophies, to ideologies, to "new age" stuff, to the worship of cultural elements of the past. Elements of animism appear to have close parallels with beliefs in objects influencing luck as well as the "rightness" of objects in one's world -- as with Feng shui
There are very few who stay sane while raging against this machine of their own mind. Perhaps this biology is entirely leftover from our earliest brain's evolutionary past, or it is that plus additional modifications over time. However it came to be, it exists. This is biology and not culture. From what I can see, some dilute version of animism is the most raw and inescapable satiation of that biology.